This script allows you to assign common events to weapons/armors that will be run when you equip or dequip (un-equip) them. The common events are assigned separately, so you might have one equip event, and another dequip event.
Script: download here
If you would like the common event to run in the scene, you will need to use something like the Scene Interpreter
Place this below Materials and above Main.
Tag your equips with
<equip event: x> <dequip event: x>
For some common event ID x.